A dry shaver having a swingable shaving head is known in the art, for example, from EP 0 239 920 A2 in which the shaving head is caused to swing or tilt by contact with a user's skin to follow a contour of the skin while manipulating to move the shaver across the skin. For this purpose, the shaving head is pivotally connected at its top end to a frame projecting on a hand grip by means of pivot pins. In this structure, the pivot pins or the associated portions of the frame have to be exposed at the top end of the shaving head very close to the cutting face of the shaving head, thus hindering the shaving operation.
In order to alleviate the problem, JP 5-200166 A proposes another dry shaver in which the shaving head is supported by use of a four bar linkage mechanism. The four bar linkage mechanism enables to eliminate the use of pivot pins and the associated parts projecting on top of the shaving head, and allows the shaving head to swing to follow the skin, while retaining an advantage of keeping an pseudo swing axis as close as to the top end of the shaving head such that the shaving head can swing with a minimum attendant displacement of the point of contact with the skin. The four bar linkage mechanism includes a pair of side links or cranks each of which is pivotally connected at its opposite ends to the shaving head and to the hand grip to constitute a double-crank mechanism. The shaving head is given support points for pivotal connection respectively with the upper ends of the individual cranks, while the hand grip is formed with anchor points for pivotal connection respectively with the lower ends of the individual cranks. Even with the use of the linkage mechanism in which the support points to the shaving head is disposed upwardly of the anchor points to the hand grip, however, there remains a problem in that the contact point of the cutting face with the skin suffers from a considerable vertical displacement away from the skin, which makes it difficult to maintain an optimum and comfortable contacting pressure with the skin.
Further, since the above linkage mechanism gives an inherent swinging characteristic that the shaving head swings only accompanied with a small angular displacement of the cranks about the anchor points, the shaving head becomes over-sensitive to a force applied to swing the shaving head. In other words, a slight pressing force might swing the shaving head far beyond a suitable position through the small angular displacement of the cranks. Such jerky movement is therefore to be avoided in order to make the shaving head to follow the skin smoothly in an optimum pressing relation with the skin.